Safety precautions to be observed with cooled premixed gases.
The gas delivered from a cylinder of Entonox (50% nitrous oxide and 50% oxygen) may not contain adequate quantities of oxygen if the cylinder has been cooled and then allowed to warm up in a vertical position.The composition of gas delivered from cylinders cooled to not lower than -40 degrees C. remains unaltered if the cylinders are rewarmed for 24 hours in a horizontal position at a temperature of not less than 5 degrees C.Cylinders of Entonox delivered in cold weather should be stored in a horizontal position at 5 degrees C. or more for at least 24 hours before use.
D000773:Anesthesia, Obstetrical; D003080:Cold Temperature; D009609:Nitrous Oxide / Q000008:administration & dosage*; D010100:Oxygen / Q000008:administration & dosage*
D009609:Nitrous Oxide; D010100:Oxygen